Horn
duos were once a popular form of music. Professional duetists
toured the capitals of Europe, and dozens of books of horn
duos were written. Some consisted mainly of the rustic calls
of the hunt, but others were clearly intended as art music.
One of the best composers of these was Louis-François
Dauprat, who began his musical career in the armies of Napoleon,
later studied composition with Anton Reicha, and served as
a professor for a quarter century at the Paris Conservatoire
National. His Opus 13 duos were published sometime between
1818 and 1824.
The
natural horn, like the valve horn, uses the harmonic series
to produce its notes. A tube of a given length will amplify
vibrations at frequencies that are multiples of the frequency
of the “fundamental” note. These so-called “open”
notes are shown below. Nineteenth-century concert reviewers and
composers frequently complained about the intonation of the four
marked notes.

The
valves of the modern horn make it possible to fill in the missing
notes of the scale. When the hornist depresses a valve,
more tubing is added to the length of the horn, creating a
new series of open notes. With three valves, every note of
the chromatic scale can be played as an open note. The natural
horn, however, fills in the missing notes with a series of
rather obscure tricks. First, crooks (detachable loops of tubing
between the mouthpiece and the body of the horn) can be used
to set the length of the tube to different fundamentals for
different keys, thus providing as many open notes possible.
Second, the composer can stick to the upper half of the harmonic
series, where there are fewer missing notes.
Third,
the hornist can raise or lower the open notes by inserting
the right hand into the bell of the instrument. Inserting the
hand all the way lowers the high notes by a half step, and
the low notes by a whole step. Inserting the hand part way
into the bell also lowers the notes, but not as much. The hornist,
like a slide trombonist, must possess a good ear, as the degree
of insertion varies depending on the note, its harmonic function,
and the dynamic level. Taking the hand out of the bell raises
the notes slightly. The sound of the horn becomes more muffled
as the hand goes further into the bell, and these notes become
edgy or brassy when played forte.
Fourth,
the hornist can “bend” the lowest open notes downwards
by deliberately buzzing the lips at a frequency below the harmonic,
and can fully stop the bell and overblow these lowest notes
to produce an unstable (and extremely ugly!) note a half step
higher. The “ugly duckling” note can be clearly
heard near the end of II:4 (2nd Duo, 4th Movement) at the fermata,
and it is immediately followed by four of the “bent” notes
in the extreme low register.
Dauprat’s
intimate knowledge of hand horn techniques makes this opus
a compositional tour de force. Not
only does he use all twelve notes of the chromatic scale in
nearly every piece, he also pioneers the use of key signatures
of up to four sharps and four flats for an instrument which
was generally restricted C major. His stated purpose in writing
these duos was to write in “all the major and minor scales
practicable on a single crook.” His ideas of what was “practicable” went
far beyond the usual practice of his time, and his goal was
at least as much aesthetic as technical. He exploited the positioning
of stopped notes to produce distinct moods and tone qualities
for each key, much as J.S. Bach did in the Well-Tempered
Clavier. For
the natural horn, C major and the sharp keys are cheerful and
brilliant because they contain many open notes. The sharped
notes are often leading tones, so the hand position is more
open than would otherwise be the case.
Dauprat
constructs several lively melodies almost entirely of open
notes, for example the C major openings of I:1, I:3, I:4, and
the Trio of II:2. The stopped notes are often placed on weak
beats or used as passing tones, so that the open notes accentuate
the meter. These same techniques work even better in G major
(I:4, measures 12-60), since F-naturals require full stopping
but F-sharps are half-stopped in the lower octave and open
in the upper octave. Dauprat uses key signatures of two sharps
in IV:2 and three sharps in parts of I:2 and IV:1.
The
flat keys (C minor and Eb major in the second duo) sound calm
or even somber. One must close the flatted notes slightly more
than normal to make them lead downwards to resolution. The
key of A minor, although it contains no more stopped notes
than C major, takes on a different character because the stopped
notes include the tonic (half-stopped) and its upper and lower
neighbors. This effect can be heard clearly in the lovely Siciliana
dance movement (I:2). The stopped notes sound veiled and mysterious,
rather than deficient. This sound was so highly regarded
that the Conservatoire National did not abolish its natural
horn curriculum until 1903!
Dauprat
pushes the natural horn to its limits in remote keys. His audiences
must have been truly startled to hear the rapid modulations
in the miniature development section of I:4 (E minor to A minor
to D minor to F major), and a retransition constructed almost
entirely of chromatic scales. The path of IV:4 is even
more adventurous, with an abrupt modulation from E minor to
F major. And V:3 (to be recorded next year) is in the unlikely
key of F minor.
Richard plays a horn made by Marcel-Auguste Raoux in the 1840s,
and Beverly plays a Finke copy of a 1830s Belgian horn, both
modified by Lowell Greer. We tuned to A=430 and used mean-tone
temperament, referring frequently to a Peterson AutoStrobe
490 tuner for guidance. |